The invention relates to a filter bag for vacuum cleaners, having a connection member, which comprises an essentially tabular main body of board-like stiff material and a closing slide guided thereby the main body possessing a fitting opening for fitting the connection member onto a connector tube of the vacuum cleaner and the closing slide has a passage opening, said closing slide being adapted to be drawn out of an open position, in which the passage opening clears the fitting opening into a closed position closing the fitting opening by means of a handle part exposed on the front transverse edge part of the main body.
Such a filter bag, disclosed for example in the German patent publication 4,002,868 C, may, when it is removed in the filled state from the vacuum cleaner, being closed by means of the closing slide so that no dust may escape into the surroundings.
In the case of the filter bag in accordance with the said the German patent publication 4,002,868 C it is necessary, before drawing the closing slide into its closed position, for the connection member to be pulled off the connector tube and for the filter bag to be removed from the vacuum cleaner. It is in this manner that a substantial amount of dust may escape into the surroundings, more especially when if, as is frequently the case, the bag is pressed against the wall of the vacuum cleaner, this being something which will cause dust to be blown out from the bag.
The European patent publication 0 362 624 relating to a filter bag similar to that in accordance with the German patent publication 4,002,868 C on the contrary proposes a design wherein the handle part of the closing slide is gripped and drawn while the connection member is still held on the vacuum cleaner. Since however direct closing of the fitting opening in the main body is hindered by the connector tube of the vacuum cleaner still projecting the fitting opening, such a firm pull is required that the main body together with the closing slide is caused to bulge out as far as a point short of the connector tube. It is then uncertain whether the closing slide will then close immediately. Owing to the strain on the connection member with the bulging effect and owing to the frictional forces it is in fact likely that on pulling on the handle part the connection member as a whole will slip out of the vacuum cleaner before the closing slide moves in relation to the main body.